The computer was derived from mechanical calculating machines which could perform arithmetic. They had levers and cogs which rotated and shifted to represent numerals. The first was constructed in 1642 by Blaise Pascal, a French inventor. Pascal's device was bettered over the following two hundred years and in 1833, Charles Babbage, a British mathematician devised equipment which could be `programmed' to act out several mathematical exercises. It was called the Analytical Engine. Babbage came up with the idea of the computer, but unfortunately he was unable to assemble it, as it was too intricate for its time. In 1991 a full working model was built in the London (England) Science Museum to Babbage's original blueprints, to dispel the myth that it would never have worked.
There are four main types of computer in use today: supercomputers (the biggest), mainframes, minicomputers, and microcomputers (the smallest). The bigger the computer, the more it can do in a shorter space of time.
The microcomputer is the most familiar to us and can be found in many homes throughout the world, two of the currently popular models being The Commodore Amiga and the Atari ST.
All computers work on the same basic concept of having input, a CPU (Central Processing Unit), memory and output.
The input devices are commonly keyboard, joystick or mouse. The CPU is a microchip inside the main housing of the computer which is able to execute instructions. The CPU works in conjunction with the memory chips which store data and lists of instructions (programs) for the CPU. The output device is usually a monitor or TV but can also be a printer.
